摘要:

DeMaggio, AugustusE. (Rutgers · The State U., Coll. of Pharmacy, Newark, N. J.), and RalphH. Wetmore.Morphogenetic studies on the fern Todea barbara. III. Experimental embryology. Amer. Jour. Bot. 48(7): 551–565. Illus. 1961.—A study of the various stages in the life history of the fernTodea barbara(L.) Moore has shown that young embryos can be removed from the surrounding prothallial tissue, within which they normally develop, and successfully grown in culture. It was possible, therefore, to investigate the manner in which the embryo develops when it is freed from the restraint of surrounding cells. Embryos excised 20 days after fertilization could be grown to mature sporophytes in a liquid culture containing mineral salts and sugar. Younger embryos, excised 17 days after fertilization, required the addition of whole coconut milk or a mixture of sorbitol and inositol, components of the “neutral” fraction of coconut milk, to complete their development. Embryos excised prior to the appearance of the first division wall, 4–5 days after fertilization, did not develop into the usual, 3‐dimensional, diploid or sporophytic plant. Instead they become irregular, rather 2‐dimensional, thalloid structures, remarkably similar to the early haploid or gametophytic plant. These findings are considered in relation to the environmental conditions of growth with particular reference to nutritional and physical factors.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1961.tb11681.x

出版商:Wiley    

年代:1961

数据来源: WILEY

摘要:

Tateoka, Tuguo. (U. Montréal, Montréal, Canada.)A biosystematic study of Tridens (Gramineae). Amer. Jour. Bot. 48(7): 565–573. Illus. 1961.—The genusTridenshas been studied from cytological, morphological, anatomical and histological points of view. Species ofTridenscan be divided into 2 groups according to the characters of caryopses, stigmas, lemmas, paleas and general habit. In accordance with the morphological disparities, the 2 groups have different appearances of the anatomy of leaf margins and midribs and also of the bicellular microhairs on the epidermis of the leaf blade. Further, the 2 groups have different basic chromosome numbers,x=8 andx=10, and some distinction in karyotype. Somatic chromosomes of 8 species have been examined. The evidence given by the combined studies indicates thatTridensshould be regarded as a mixture of 2 phylogenetically distant groups. Based on this conclusion, the 5 species representing one of the 2 groups (T. pilosus, T. avenaceus, T. grandiflorus, T. nealleyiandT. pulchellus) are transferred to the genusErioneuronwhich is hereby revived. Nomenclatural changes are made for the species of the revived genus.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1961.tb11682.x

出版商:Wiley    

年代:1961

数据来源: WILEY

摘要:

Tanaka, R., and H. Kamemoto. (U. Hawaii, Honolulu.)Meiotic chromosome behavior in some intergeneric hybrids of the Vanda alliance.Amer. Jour. Bot. 48(7): 573–582. Illus. 1961.—Meiotic chromosome behavior of 11 groups of diploid intergeneric hybrids (2n=38) of theVandaalliance was investigated.VandaMiss Joaquim ×Luisia teretifoliaandAscocentrum curvifolium×Vanda lamellatausually produced 19 bivalents at metaphase I, indicating good homology of the parental chromosomes.Vanda tricolorvar.sanderae×Vandopsis lissochiloides, Vandopsis lissochiloides×Vanda sanderiana, Vandopsis lissochiloides×VandaTatzeri andArachnis flos‐aeris×Vandopsis lissochiloidesshowed fair homology of parental genomes with formation of 12–15 bivalents at metaphase I.Trichoglottis brachiata×Vanda sanderiana, Vanda tricolorvar.purpurea×Phalaenopsis denevei, VandaTatzeri ×Aerides lawrenceae, Renanthera monachica×Vanda luzonica, Renanthera storiei×VandaClara Shipman Fisher andAerides lawrenceae×Saccolabium giganteum, formed an average of 2–7 bivalents, thereby indicating poor homology of parental genomes. The hybrids,Renanthera monachica×Phalaenopsis sanderianaandArachnis hookeriana×Vanda suavis, lacked chromosome pairing. On the basis of chromosome affinity at meiosis, a cytotaxonomic scheme was developed for the several genera of theVandaalliance studied. Cytotaxonomy, evolution and breeding behavior in theVandatribe were briefly discussed.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1961.tb11683.x

出版商:Wiley    

年代:1961

数据来源: WILEY

摘要:

McManus, SisterMaryAnnunciata, R.S.M. (Mt. Mercy Coll., Cedar Rapids, Iowa.)Culture of Stemonitis fusca on glass. Amer. Jour. Bot. 48(7): 582–588. Illus. 1961.—The plasmodium ofStemonitis fuscadiffers in morphology from the type which has been considered characteristic of all Myxomycetes. It lacks the dense granules which are numerous in the physaraceous plasmodium and is, therefore, delicate and transparent, becoming macroscopically visible only when it is about to fruit. It never forms the thick, fleshly fan which is characteristic of the physaraceous type. A simplified method of culture on glass has been developed, which permits excellent visualization of the stages of the life cycle under high magnification and by phase‐contrast illumination.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1961.tb11684.x

出版商:Wiley    

年代:1961

数据来源: WILEY

摘要:

Piringer, A. A.,andH. A. Borthwick. (U.S.D.A., Beltsville, Md.)Effects of photoperiod and kind of supplemental light on growth, flowering and stem fasciation of Celosia.Amer. Jour. Bot. 48(7): 588–592. Illus. 1961.—Four cultivars ofCelosia argenteaL. var.cristatawere grown on photoperiods ranging from 8 hr to continuous light. Supplemental low‐intensity incandescent light was used to extend 8 hr of natural light and provide the given photoperiod. In all cultivars, short main stems occurred on photoperiods of 12 or fewer hours and long main stems, due to more nodes, on photoperiods of 16 or more hours. Flowering was a nonobligate short‐day response in all cultivars. Plants of certain cultivars tended to have shorter stems and flower later when 8 hr of fluorescent instead of incandescent light was used to provide the 16‐hr photoperiod. In 3 of the cultivars studied, photoperiods of 16 or more hours induced marked stem fasciation.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1961.tb11685.x

出版商:Wiley    

年代:1961

数据来源: WILEY

摘要:

Boke, NormanH. (U. Oklahoma, Norman.)Areole dimorphism in Coryphantha.Amer. Jour. Bot. 48(7): 593–603. Illus. 1961.—Coryphantha clavaandC. erectahave both grooved and grooveless tubercles. The latter occur on young plants and emergent branches and may occur mixed with grooved tubercles on adult shoots, especially inC. erecta.Grooved tubercles have monomorphic areoles and are the only ones which bear flowers. The dimorphic areoles on grooveless tubercles develop exactly as in the mammillarias. In both species capitate glands occur in the axils of most tubercles and may occur at any position along an areole groove. The glands are initiated by the areole meristem in the same manner as spines, with which they are homologous. Close relationship between the 2 species is substantiated by both ectomorphic and endomorphic characters. The possession of both monomorphic and dimorphic areoles may mean that these cacti are evolving toward the complete areole dimorphism manifested by the mammillarias.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1961.tb11686.x

出版商:Wiley    

年代:1961

数据来源: WILEY

摘要:

Hackbarth, R. D., and R. P. Collins. (U. Connecticut, Storrs.)A study of the vitamin requirements of three species of the genus Gelasinospora.Amer. Jour. Bot. 48(7): 603–606. Illus. 1961.—The vitamin requirements of 3 species ofGelasinospora(G. tetrasperma, G. retispora, G. cerealis) were determined. Various combinations of the 10 vitamins used in the study were tried and biotin was found to be the factor limiting growth.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1961.tb11687.x

出版商:Wiley    

年代:1961

数据来源: WILEY

摘要:

Walker, S. (Liverpool U., England.)Cytogenetic studies in the Dryopteris spinulosa complex. II.Amer. Jour. Bot. 48(7): 607–614. Illus. 1961.—A comparison of theD. spinulosacomplex, as represented in North America, is made with that in Europe. Although in North America, otherDryopterisspecies are known to hybridize with members of the complex, the report has been limited to species which compare directly with those in Europe. Three tetraploid species and 2 diploids, the latter representing at least 1 ancestral genome in the complex, are discussed together with the interspecific hybrids. Synthetic hybrids have been produced, involving taxa from both sides of the Atlantic. Evidence from these hybrids suggests thatD. intermedia, of North America, andD. maderensis, of Madeira, are conspecific.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1961.tb11688.x

出版商:Wiley    

年代:1961

数据来源: WILEY

摘要:

Weier, T. Elliot. (U. California, Davis.)The ultramicro structure of starch‐free chloroplasts of fully expanded leaves of Nicotiana rustica.Amer. Jour. Bot. 48(7): 615–630. Illus. 1961.—The grana of starch‐free chloroplasts of fully expanded leaves ofNicotiana rusticaare distinct, compartmented, subplastid entities. They vary in size, shape, orientation and in the distinctness with which their compartments are delineated. It has not been possible to equate accurately their micro and ultramicro appearances. At the ultramicro level, the grana are connected with each other at irregular intervals by a system of anastomosing channels. The partitions forming the compartments of the grana may be coarse or very fine but are constant in appearance in any given chloroplast. The loculi enclosed by the partitions may vary in size with a granum, depending upon their location or upon the physiological activity of the chloroplast. The stroma does not penetrate the grana; it may be relatively fluid and the grana‐fretwork system may move within it. A double envelope, which may have pores connecting stroma and hyaloplasm, surrounds the chloroplasts. Materials may collect between the surfaces of the envelope. There is considerable variation in the ultramicro details of chloroplast structure ofNicotiana rustica.It is not yet possible to distinguish accurately between those variations which may be of physiological significance and those which may be induced by processing.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1961.tb11689.x

出版商:Wiley    

年代:1961

数据来源: WILEY

摘要:

McGahan, MerrittW. (Central Research Labs., United Fruit Co., Norwood, Massachusetts.)Studies on the seed of banana. II. The anatomy and morphology of the seedling of Musa balbisiana.Amer. Jour. Bot. 48(7): 630–637. Illus. 1961.—The first external evidence of germination of the seed ofMusa balbisianais the displacement of the micropylar plug by the elongation of the hypocotyl‐radicle axis. As the hypocotyl and epicotyl emerge from the micropylar collar, the seminal adventitious roots become apparent and the cotyledonary sheath surrounding the epicotyl emerges as a coleoptile‐like structure. Subsequent growth results in the elongation of the first leaves beyond the cotyledonary sheath and the rapid elongation of the adventitious root system. The vascular transition occurs between the cotyledon and the radicle. The sheath is considered to be only analogous to the coleoptile of the grasses.

ISSN:0002-9122    

DOI:10.1002/j.1537-2197.1961.tb11690.x

出版商:Wiley    

年代:1961

数据来源: WILEY